Sleep and Breathing

Davina LovegroveSenior Scientist & Training Coordinator

Respiratory and Sleep Specialists

Sleep – Why do we need it?

• Restorative function for brain • Learning and memory• Repair of cells and healing• Hormone secretions• Energy conservation

How much is enough?• Children and teenagers

– average of 10 hours per night

• Adults– Average of 8 hours per night

Hours of sleep /night 4 5 6 7 8 9 10 11 12

Consequences of reduced sleep

• Day time tiredness• Reduced reaction times• Mood disturbances• Fatigue & muscle weakness• Headaches• Double vision• Reduced motivation……..

Sleep Hygiene

What is sleep hygiene?• Sleep quantity• Bedroom / sleep routine

– Regular bedtimes– Routine before bed *– Dark environment– No bright lights– No pets in the room– No TV, computers & work in bed– Caffeine intake

Sleep Disorders• Sleep Apnoea• Insomnia• Narcolepsy• Periodic Limb Movements• Insufficient sleep syndrome• Post Traumatic Hypersomnia• Obesity Hypoventilation• Respiratory Failure• Night Terrors• REM Behaviour Disorder• Nocturnal Epilepsy

Obstructive Sleep Apnoea

What is OSA?• repeated obstruction of the upper airway during sleep

causing;– reduction in blood oxygen saturation – frequent sleep disturbance

Phillips & Naughton, 2004

How do we diagnose OSA?• Risk factors

– Obesity– Family history– Age – Smoking– Alcohol / sedative use

• Questionnaires– Epworth sleepiness scale

• Overnight sleep study (PSG)

How do we diagnose OSA?

ENLARGED UVULA

ELONGATED PALATAL FOLDS

NARROWUPPER AIRWAY

APERTURE

BACK OF TONGUE

Clinical Examination – risk factors

What happens when an individual obstructs?

Normal Airway

Snoring

What happens when an individual obstructs?

Apnoea

What happens when an individual obstructs?

Slide courtesy of Dr Darren O’Brien

Consequences of OSA• Sleep disruption• Headaches• Hypertension• Heart disease (heart failure, CAD)• Type 2 diabetes / insulin resistance• Increased risk of stroke• Heart arrhythmias• Intellectual deterioration• Frequent urination at night• Personality changes

SpO2

BP

AirflowResp. effort

Treatment optionsLifestyle changes

– Weight loss– Drugs, alcohol, smoking– Sleep hygiene

Positional therapySurgery

– Tracheostomy– Uvulopalatopharyngoplasty– Gastric, bariatric Sx

Oral appliancesCPAP/APAP/Bilevel

Slide courtesy of Dr Darren O’Brien

• Gold Standard treatment• How it works

– Air passes through a mask into your nose and/or mouth then into your throat, where the slight pressure acts as a splint to keep your airway open and prevent apnoeas, hypopnoeas and snoring.

CPAP

CPAP

First Patient on CPAP, RPAH, 1980.

Sullivan et.al., Lancet 1981

Slide courtesy of Dr Darren O’Brien

Fixed Pressure CPAP Devices

10 cm H2O

Fixed pressure throughout the night

CPAP machines provide a single, fixed pressurethrough out the night.

The intent of CPAP is to splint open the upper airwayto prevent obstruction.

Auto Pressure CPAP Devices

4 cm H2O

Beginning of obstruction

Varying pressure throughout the night in response to events

Auto pressure devices automatically adjust the pressure in response tochanges in the patients airway.

Results in lower overall mean pressure. ?increased comfort for patient.

Bi-level Devices(NIV)

• Bi-level systems deliver two different pressures– a higher pressure on inspiration (IPAP)– a lower pressure on expiration (EPAP)

• Acts as a non-invasive VENTILATOR (NIV)

4 cm H2O

10 cm H2O

Inspiration

Expiration

Why do we need bi-level?

• Breathing basics….

In order to breath INour diaphragm and accessory chest muscles must contract to cause expansion of our rib cage and therefore air enters our lungs

When do we need bi-level?• When our diaphragm cannot

contract due to– Muscle weakness– Greatly increased load on the

muscles– Restricted movement

Breathing basics – gas exchange• With each breath our lungs transfer

– Oxygen (O2) from the air into our blood stream– Carbon dioxide (CO2) from our blood into the air

• When we don’t breath adequately– Blood oxygen levels drop (hypoxia)– Blood carbon dioxide levels increase (hypercapnia)

CO2

O2

CO2

O2

Breathing basics

• Not breathing adequately is called HYPOVENTILATION

• Hypoventilation hypoxia + hypercapnia

• Hypoxia + hypercapnia = respiratory failure= hospital admission

How does bi-level help?

• Assist and support patient’s own breathing efforts

• Rest fatigued respiratory muscles• Improve gas exchange by increasing tidal volume• Prevent nocturnal hypoventilation

• Increase nocturnal O2 levels

• Reduce nocturnal CO2 levels

• Improve daytime blood gases

• Stabilise upper airway

Case study

• Chest wall restriction secondary to Poliomyelitis

• Undergoing a split night sleep study– ½ night as a diagnostic study– ½ night as a bi-level study

Dx NIV

Research

• Simonds et al 1995:• Outcomes of patients on home NIV were assessed

over 5 years in 180 patients with chronic respiratory failure

• NIV very well tolerated in post-polio patients:– 100% (n=30) of patients were still compliant at 5 year

follow-up (ie 100% survival at 5 years)– Blood oxygen (O2) and carbon-dioxide (CO2) levels were

improved and maintained at 5 years

Research

• Leger et al. 1994• NIV improved quality of life• NIV reduced number of days in hospital (from an

average of 34 days per year to 7 days per year)• NIV improved sleep quality in 70% of patients

• Buyse 2002• NIV is more beneficial in terms of survival, blood

gases, and lung function compared with long term oxygen alone in patients with kyphoscoliosis

Why use NIV as treatment?

• Improved sleep quality• Improved quality of life• Less hospital admissions• Improved blood gases (CO2 and O2)• Improved lung function